Unit test api

* adds unit test for APIUserToken
* enhances handling of token fetching for API

api/views/views.py

@@ -53,7 +53,13 @@ class AbstractAPIView(View):
             # Fetch the proper user from the given request header token
             ksp_token = request.headers.get(KSP_TOKEN_HEADER_IDENTIFIER, None)
             ksp_user = request.headers.get(KSP_USER_HEADER_IDENTIFIER, None)
-            self.user = APIUserToken.get_user_from_token(ksp_token, ksp_user)
+            token_user = APIUserToken.get_user_from_token(ksp_token)
+
+            if ksp_user != token_user.username:
+                raise PermissionError(f"Invalid token for {ksp_user}")
+            else:
+                self.user = token_user
+
             request.user = self.user
             if not self.user.is_default_user():
                 raise PermissionError("Default permissions required")